Old Unibus PDP-11 XXDP diagnostics

From: Guy Sotomayor <ggs_at_shiresoft.com>
Date: Tue Dec 21 11:14:56 2004

On Tue, 2004-12-21 at 08:27, Ashley Carder wrote:
> Does anyone have any info/documentation on the XXDP diagnostics for
> older PDP-11 systems and peripherals? I'm looking in particular for
> the 11/40 (11/35), RK05, DZ11, RL02, MM11 core memory, RX01, RL01
> diagnostics. I have found some info on Henk's site, but would like to
> know if anyone has a comprehensive list and hints on how to run these,
> what the output means, how to answer the prompts, etc.
> I have created RL02 packs with XXDP 2.5 and XXDP 2.2 and I can boot
> and run stuff from these packs. It appears that the 11/40 diagnostics
> are on XXDP 2.2, but not on XXDP 2.5. I have an old 1976 DEC field
> rep troubleshooting guide that refers to various MAINDECs, which seem
> to have been the diagnostics prior to XXDP. Is there a list somewhere
> showing what the XXDP equivalents of the old MAINDECs are?

OK, the "magic decoder ring" for converting the MAINDECs to XXDP names
is quite simple. The MAINDEC # is of the form:

To convert this to the XXDP diagnostic name keep only the xxxx part of
the MAINDEC #. To run it, do:
        R xxxx??

The first letter in the diagnostic name tells you what processor it's
for. If I remember correctly C=11/40, Z=any

There's a document that tells all about it (but I can't remember where I
found it at the moment).

The pack images that you're talking about don't have the correct memory
diagnostic, but I've found that ZMSDD0 (wow! from memory...can you tell
I've used it a bunch?) works OK enough to be able to find bad memory and
you'll know when you hit bad memory. I've also found that having a
hardcopy terminal is preferable to a CRT when you're getting failures.

If a diagnostic loads and then gives you a prompt like "DB>", START is a
good choice as a response.

> Any help would be appreciated. I want to exercise my 11/40 and
> attached peripherals and see if any subtle gremlins are lurking
> anywhere within. Everything appears to be working perfectly with the
> exception of one of my three RK05 drives that I knew was problematic.
> Ashley
TTFN - Guy
Received on Tue Dec 21 2004 - 11:14:56 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:36:39 BST